5 speed vs 6 speed vs 6 speed with JDM MR gears...

**thor'svr4** · 10-30-2010, 06:31 PM

so ive got a semi bad syncro on 2nd gear right now. i was thinking about replacing it, or buying a 6 speed trans. the prob is the 5 speed has perfect gearing for my car in the 1/4 mile right now since im right about at redline in 3rd as i cross the line. if i get the 6 speed i think ill have to shift into 4th gear which might cause me to loose some time. but what about the 6 speed with MR gears? are they short enough that i could grab 4th and actually use 4th gear?

I’ve searched stealth316 and cant find any info on the MR gears.

as far as i can tell (without any slips from the track) my trap speeds are more or less in-between the orange dots on the pic below. obviously my speedo / tach could be slightly off or my '1/4 mile' could be a little shorter or longer than 1320' but nothings an exact science on the street.

you can see the 6 speed's 3rd might be a little to short, and the 5 speeds 3rd is pretty good but what about the 6 speed MR? would it work just as good or maybe even better than the 5 speeds 3rd gear? anyone have any good info on it?

**stealthee** · 10-30-2010, 06:38 PM

Cant help with the question, but ALL JDM 6 speeds had the shorter gearing, not just MR's. Just wanted to correct that.

**Polygon** · 10-30-2010, 06:39 PM

I thought about doing this and it's more than swapping a trans. You have to swap the rear diff as well. There could be more work depending on if your an 18 spline or not. My conclusion was that it wasn't worth it.

**stealthee** · 10-30-2010, 06:43 PM

5 speed 3s's won't need to swap rear diffs if using JDM 6 speed gearing.

**thor'svr4** · 10-30-2010, 06:58 PM

Originally Posted by stealthee

5 speed 3s's won't need to swap rear diffs if using JDM 6 speed gearing.

so i should only need the trans, t case, and maybe a drive shaft?

Originally Posted by 3000GT MR

I hit 4th with time to use it with TD04 running 118 traps

im assuming from you username it was with the MR 6 speed right?

**Polygon** · 10-30-2010, 07:00 PM

Originally Posted by stealthee

5 speed 3s's won't need to swap rear diffs if using JDM 6 speed gearing.

Ah, good to know.

**GTOJOE** · 10-30-2010, 11:01 PM

Originally Posted by stealthee

5 speed 3s's won't need to swap rear diffs if using JDM 6 speed gearing.

Correct. Both are the same ratio. However the drive shafts are different between 5 and 6 speed. How do you get around this?

**stealthee** · 10-31-2010, 12:03 AM

Originally Posted by GTOJOE

Correct. Both are the same ratio. However the drive shafts are different between 5 and 6 speed. How do you get around this?

As was stated in a previous post all you need to swap is the front section of the driveshaft to the 6 speed style.

**GTOJOE** · 10-31-2010, 12:06 AM

Originally Posted by stealthee

As was stated in a previous post all you need to swap is the front section of the driveshaft to the 6 speed style.

Shit didn't read that. My bad

**donniekak** · 10-30-2010, 08:19 PM

Originally Posted by Polygon

I thought about doing this and it's more than swapping a trans. You have to swap the rear diff as well. There could be more work depending on if your an 18 spline or not. My conclusion was that it wasn't worth it.

When you swap in a jdm 6-speed, it uses the 5-speed rear end. You just need the front section of a 6-speed driveshaft.